This study may shine a bit more light-
Nicotine Replacement Therapy Modestly Boosts Long-term Success Rates for Smokers
"Researchers from the Institute of Social and Preventive Medicine in Switzerland identified all randomized placebo-controlled trials of NRT that lasted longer than 12 months. Twelve studies with an average follow-up of 4.3 years and a total of 4,792 participants (NRT: 2,408; placebo: 2,384) met the criteria for this meta-analysis.
Three types of NRT were studied: patch (5 trials), gum (4), and nasal spray (3); each delivered about 1 mg of nicotine per hour. Participants used NRT for about
three months and received counseling; the control groups only received counseling. The researchers, therefore, were able estimate the long-term effectiveness of NRT beyond the effect of counseling."
"In both the treatment and placebo groups, 30% of volunteers relapsed after the 12-month point. NRT showed significant benefits in six of the 12 trials, and no benefit in the other six. But when all the data were combined and analyzed, NRT almost doubled the rate of successfully quitting beyond 12 months. However, since the rate of success was quite low, even a doubling of this rate meant success for only about 7% of the 2,408 participants receiving NRT in this meta-analysis."
Basically, I read that to mean that the long term effectiveness of cold turkey is around 3.5% with traditional NRT long term success at 3.5% better success, still pretty ineffective. I'm sure Chantix has a better quit rate, but as posted, there are some serious consequences in using the drug. Also working backwards, based on the 30% relapse after one year, the average quit rate at one year would be around 10% for the NRT studied. So if the average of the Spray, Patch and Gum were 26.4% at six months, another 62% were lost between month 6 and one year.